Refrigeration



Patented Dec. 6, 1927i.

UNITED STATES PATENT oFFlcE.

NILS PERSSON, OF STOCKHOLM, SWEDEN, ASSIGNOR T ELECTROLUX SERVEL COB- POBATION, 0F NEW YORK,

A CORPORATION OF DELAWARE.

REFRIGERATION.

Application filed March 9, 1927, Serial No. 173,893, and in Germany March 2, 1926.

My invention relates to the art of refrigeration and particularly to refrigerating apparatus of the absorption type and still more particularly to absorption systems in I which the circulation of fluids is effected by forces generated within the system.

One object of my invention is to provide means for regulating the refrigeration effect obtained from such a system by regulating the heat supplied thereto while at the same time maintaining constant forces utilized to promote circulation of fluids therein.

In refrigerating systems used in domestic cabinets, the amount of refrigeration required depends chieliy upon the temperature of the room in which it is situated. By means of my invention I propose to regulate the amount of refrigeration by a preferably manually operated control which varies the quantity of heat supplied to the generator.

`urthermore, I propose to provide or temporary fluctuations in the amount of refrigeration required, due to opening of the doors and the like, by providing storage of cold in a brine tank, a metal casting or in frozen ice. These and other objects and advantages will be apparent from the following description and accompanying drawing on which:

Reference character designates a generator which is divided into a main generator 11 and an auxiliary generator 12 by a partition 13. A pocket 14 extends centrally through auxiliary generator 12 and some distance within main generator 11. Within pocket 14 is situated a metallic sleeve 15 which serves as a retainer for several electrical heating resistances 5, 6, 7 and 8. One of these, resistance 5, is so situated Within sleeve 15 as to be adjacent to auxiliary generator 12 while the remainder are situated within the sleeve so as to be adjacent to main generator 11. One end of eachresistance coil is trical conductor 16 while a separate conductor connects the other end of each resistance coil 5, 6,7 and 8 with contact points 1,2, 3 and 4 respectively. A contactor 18 is mounted on an arm 19 which is pivoted at 20. Arm 19 is rigidly'connected to arm `21 OFM.

electrically connected to elec-y which is pivotally connected at 22 to a rod 23. Rod 23 is pivotally connected at 24 to an arm 25 which is pivoted at 26 and attached rigidly to a handle 27. Arms 25 and 21 are of the same length. Thus movement of the handle 27. around pivot 26 causes a similar movement of arm 19 around pivot 20 and causes contactor 18 to slide over contacts l, 2, 3 and 4. Contactor 18 `is connected electrically to conductor 17 through arm 19 and va suitable electrical connection at 20. Contacter 18 is made in the form of a sector and of a suiicient length 'to make contact with all the contact points at one time When in its extreme left hand position as viewed in the drawing.

One end of arm 23 is pivotally connected at 28 to an arm 29 which is ivotally connecter at 30 to valve stem 31. nates a valve which is placed in conduit 33 and which controls the cooling water supumeral 32 desigplied to the refrigerating system. Movement y valve 32. lVhen contactor 18 is moved to the right so that it does not make contact with any of the con-l tacts, valve member 35 is seated in valve seat 36 and iow through valve 32 is completely stopped.

While I prefer to show this part of the invention carried out as described and shown, it is to be understood that other means may be used to obtain the same result yWithout detracting from the spirit of the invention.

A conduit 37 connects the upper part of main generator 11 with the lover part of rectifier member 38. One leg ofa U-shaped member 39 is open at the top 'and extends within member, 38. The portion of member 39 within member 38 is provided with a' series otbaHes 40. A conduit 41 communicates with the upper part of member 38, extends in a generally downward direction through water jacket 42 and communicates with the right leg of member 39 as shown in the drawing. A conduit 43 connects the upper part of the right leg oi' U-shaped member 39 with heat exchanger 44.

A conduit 45 comunicates with U-shaped member 39 at a point near the bottom thereof, extends downwardly within conduit 46, horizontally within heat exchanger 44 and upwardly within conduit 47 to within evaporator 48. Evaporator 48 is a cylindrical member closed at the top and provided with a series of disks 49. Apertures 50 around which are formed raised" rims 51 are provided in disks 49. A conduit 52 connects evaporator 48 with space 53 which is formed within heat exchanger 44 between tube heads 54 and 55 and around tubes 56 and conduit 45. A conduit 57 connects space 53 with the lower part of absorber 58.

Absorber 58 is a cylindrical member in which is situated a series of disks 59 which may be similar'to disks 49 in evaporator 48. Absorber 58 is partially surrounded by a Water jacket 60. Water jacket 60 is supp ied with cooling water through conduit 33 in which is situated valve 32. The cooling Water is discharged from water jacket 60 through conduit 61 to water jacket 42 from which it is finally discharged through conduit 62.

A conduit 46 connects the upper part of absorber 58 with space 63 formed within heat exchanger 44 between tube head 54 and the adjacent end oi the heatcxchanger. A number of tubes 56 extend between tube heads 54 and 55 and connect space 63 with space 64. Space 64 is formed within heat exchanger 44 betweentube head 55 and the adjacent end of the heat exchanger. A conduit 47 connects space 64 with the upper part of evaporator 48. Evaporator 48, conduit 47 and a portion of heat exchanger 44 are contained within a brinei tank 65 which is provided with a filling plug 66. Brine tank 65 is placed 'within the'- space to be refrigerated represented by the rectangle 67.

A conduit 68 connects the bottom of absorber 58 with the upper part of auxiliary generator 12 and passes within heat exchanger 69. A thermo-Siphon lconduit 70 connects auxiliary generator 12 with the. upper part of main generator 11. Conduit 04 extends downwardly for some distance withinauxiliary generator 12 and this downy wardly lextending'portion is provided with one or more capillary ports 71. The upper end of conduit 70 communicates with main generator `11 at a point slightly below the surface of the liquid therein. A conduit 72 connects the lower part of main generator 11 y-in conduit 47 and thus with one end of heat exchange member 69. The other end of member 69 is connected by conduit 73 with the upper part of absorber 58. A portion ot conduit 73 passes Within water acket 60.

l The operation of the apparatus is as folows:

Assume first that the maximum refri erating effect of the apparatus is require to maintain the desired low temperature in compartment 67. Handle 27 is moved to its extreme right hand position which moves contacter 18 to the left until it makes contact with all of the contacts l, 2, 3 and 4. Hence an electrical connection is established between one end of each resistance coil 5, 6, 7 and 8 and conductor 17. As the other end ot' each coil is permanentl connected to conductor 16, current flows tirough, and heat is generated in, each of these coils. This heat is transmitted to the solution of a refrigerant, for instance ammonia, dissolved in an absorbin medium, for instance water, which is contained in main generator 11 and auxiliary generator 12. Auxiliary generator 12 receives its heat mainly from coil 5 while the main generator 11 is heated mainly by coils 6, 7 and 8.

The application of heat to the solution in main generator 11 causes the ammonia to pass out of solution as a vapor and ass upwardly through conduit 37 to rectifier member 38. Any water vapor which may pass into member 38 with the ammonia vapor is condensed when it comes in contact with fins 40 on U-shaped member 39. These iins are kept below the boiling point of water by the liquid ammonia within member 39. The water thus condensed collects in the bottom of member 38 and finally runs back through conduit 37 to main generator 11,

The dry ammonia vapor passes from member38 to conduit 41 where it is condensed to a liquid by the cooling water in water jacket 42 and runs into the right leg of U- shaped member `39. The level of the liquid ammonia in member 39 maintains itself at a point very slightly above the highest point in conduit 45. Hence gravitational flow takes place from member 39 through conduit 45 to the upper part of evaporator 48.

Within evaporator 48 the liquid ammonia is distributed over disks 49 and thus brought in intimate contact with a gas, inert. with respect toammonia, for instance hydrogen, which is introduced through conduit 47. The ammonia evaporates in the presence of the hydrogen and a drop in temperature occurs, which produces refrigeration. The gaseous mixture of the ammonia and hydrogen thus formed has a greater specific weight than the relatively pure hydrogen asses downwardly through apertures 50 to t ebottom of evaporator 48. The mixture passes from the hydrogen mixture in space 53 lstrong solution within conduit 68.

evaporator through conduit 52, through space 53 within evaporator 44, and through conduit 57 to within the lower part of ab contact with water which passes down-Y wardl over disks 59. This water contains but relatively little ammonia in solution and so absorbs the ammonia from the mixture and leaves the hydrogen. The greater part of the heat generated by the absorption process is carried away by the cooling Water in water jacket 60. Circulation of water takes place through water jacket 60 inasmuch as valve 32 in conduit 33 is open and allows maximum How therethrough. The light hydrogen passes upwardly through the absorber and through conduit 46, space 63, tubes 5G, space 64, and conduit 47 to the upper part of evaporator 48 where it again mixes with ammonia. Within heat exchanger 44 the liquid ammonia in conduit 45 and the hydrogen in tubes 56 is pre-cooled before entering the evaporator by the gaseous ammonia which has just left the evaporator.

The strong .solution of ammonia in water which is formed in absorber 58 passes out the bottom thereof' and runs by gravity through conduit 68 to the upper part o auxiliary generator 12. Here the solution is heated, chiefly by coil 5 and vapor is formed in the upper art of the auxiliary generator. The vapor tius formed enters thermo-siphon conduit 70 through the capillary ports 71 and reduces the specific gravity of the iiuid therein to such an extent that the level of the liquid column in and below absorber 58 is suiicient to force the fluid in -conduit 70 upwardly into the upper part of main generator 12. Within main generator 12 the ammonia is again driven out of solution as previously described and the weak solution passes downwardly therethrough and through conduit 72 to heat exchanger 69. Here the weak solution preheats the From heat exchanger 69 the weak solution flows through conduit 73 wherein it is cooled by cooling water in water jacket 60', and enters the upper part of absorber-58.

Assume next that the tem erature is reduced in the room in whic compartment 67 is situated. Less heat flows into compartment 67 and hence less refrigerating e'ect is required to maintain the desired temperature therein. Handle 27 is moved oneY step in a clockwise direction. Contactor 18 now makes contact with only contacts 1,' 2 and 3. Hence no current passes through resistance 8 and main `generator 11 is heated 4only by resistance-s 6 and 7. Therefore, less ammonia is driven out of solution and there is less ammonia supplied to evaporator 48 for evaporation and less refrigerating eect is' obtained. However, the heat supplied to auxiliary generator 12 has not been diminished'and the forces promoting circulation between the generator and absorber are the same. Also, the flow of cooling water through valve 32 has not been decreased, for, although valve member 35 has moved closer to valve seat 36, it is still at a sufficient distance therefrom to allow maximum i'low as has been previously explained.

Upon a further reduction of room temperature a corresponding reduction in retrigeratingefi'ect is obtained by moving handle 27 another step, when contactor 18 will make contact with only contacts 1 and 2. Resistances' 7 and 8 are now cut out and heat is supplied to main generator 11 by resistance 6.` of 4heat is supplied to auxiliary generator 12 and circulation is not impaired. The iiow of cooling water through valve 32 also remains the same.

Any temporary variations in the amount ot refrigerating effect required, caused b the opening of doors of compartment 67 and placing warm food therein, are equalized by the cold stored in brine tank 65 in combustion with other features above f described.

In case it is desired to stop the operation of the apparatus entirely handle 27 is moved in a clockwise direction as far as it will go. Contactor 18 does not make contact with any of the contacts and no current flows and no heat is supplied to either main generator 11 or auxiliary generator 12. Also, valve member 35 is seated on valve 'seat 36 land no cooling water flows through valve 32.

While I have shown and described a more or less specific form of my invention, it is to be fully understood that it is for purposes of illustration only and I am not to be limited thereby except in view of the appended claims. For instance, if an air cooled rectilier is employed I would prefer to control the air supplied thereto by shutters or the like operated by handle 27. Instead of electricity, gas may be used as a heating medium, the supply of gas being controlled by operating valve mechanism in the gas supply.

Having thus described I claim is:

1. Absorption refrigerating apparatus comprising a main generator for producing vaporous refrigerant, an auxiliary generator for circulating absorption liquid, means to heat the generators and means to vary the supply of heat to the main generatorwhile maintaining the supply ot heat to the auxiliary generator constant.

2. That improvement in the art of refrigniy invention, what However, the same quantity erating through the agencyof an absorption system which consists in expelling refrigerant to be evaporated from solution by application of heat, circulating absorption liquid in the system by application of heat, varying the heat applied to expel refrigerant in accordance with demand for refrigeration and maintaining a constant application of heat to circuzlate the absorption liquid While the system is in operation.

3. Absorption refrigerating apparatus comprising a generator, a condenser, an

absorber, cooling means for the condenser and absorber, a series of electric heating elements for heating said generator, means to successively supply current to said heating elements and means to maintain a constant circulation of absorption liquid and a con stant rate of cooling to remove the heat of absorption While the heating elements are successively supplied with or deprived of current.

4. That improvement in the art of refrigerating through the agency of a continuously operating absorption apparatus which consists in varying the supply of liquid refri erant to the place of evaporation in accor ance with the demand for refrigeration While maintaining a continuous constant circulation of absorption liquid.

` 5. Absorption rerigerating apparatus comprising a main generator, anabsorber, means for circulating absorption llquid between the generator and absorber, means to cool the absorber, means to heat the main generator, and interconnecting means between the circulation means, cooling means and heating means operating to simultaneously actuate the same to give full cooling cii'ect and full circulating elfect on initial actuation and successively increasing heating etlects on continued actuation.

(3. That improvement in the art of refrigerating through the agency of an absorption systeml which comprises simultaneously controlling the l'low of absorption liquid and liquid refrigerant so as to vary the supply 'ot' liquid refrigerant to the place of evaporation While at ythe saine time maintaining a constant circulation ot absorption liquid.

In testimony whereof I hereunto aix my signature.

N ILS PERSSON. 

